Three-point suspension spring construction for automobiles and like vehicles



Jan. 6. 1925.

F. N. SPRAGUE THREE-POINT SUSPENSION SPRING CONSTRUCTION FOR AUTOMOBILES AND LIKE VEHICLES Filed Feb. e, 1923 )Nm mmm Patented Jan. 1925.

unirse shares teramo PATENT FRANK N. SPRAGUE, OF HOLYOKE, COLORADO.

THREE-POINT SUSPENSION SPRING CONSTRUCTION] 1f013t1AUTOIVIOBILSNZDMIJIKQE;l

Y:Ell-IIC1335955v Application filed Februaryy 6, 1923. Seriall No. 617,353.`

struction or Automobiles and like Vehicles,`

of whichV the followingis a specification.

My invention relates to improvements in three point, suspensiony spring construction for automobiles and like vehicles.

They main object of the invention is to provide a springconstruction by which, the automobile body is spring-.supported at its rear end at three points, namely, upon opposite sides of the rear portions et the trame, and at a point midway/f between the rear ends of-the frame, whereby greater flexibility in the spring action is obtained when obstrucy tions are encountered by both real? Wheels,v simultaneously, or by either one of the said wheels. l

Further.. to provide a rear springl con,- struction for automobile bodies comprising two semi-elliptic side springs, and a full elliptic rear spring, the latter spring being interposed centrally between cross bars, which are secured, respectively to the rear ends of the side bars, and the rear ends of 3o theA side springs, whereby the resiliency of both side springs is obtained by means of the evener effect of the elliptic springytof gether with rthe cushioning action of the said elliptic spring,l particularly where obstruc.

tions areencountered by the rear wheels independently.

Further, to provide a. spring construction.

which ,practically eliminates side sway, and

sdeioltto the car body, and which canbei installed onV cars; in present use, without necessitating changes either in the side bars, or the construction of the side springs with which the car isprovided These objects are accomplished by the mechanism illustrated in; the accompanying drawings, in which:

Eig. 1 is a side View ofthe rear portion of the, frame or chassis of an automobile, showingY the improved spring construction in connection therewith.

Fig. 2 is a rear view of Fig. 1.

Fig. Sis an enlargedplan viewvpartly in. section showing a portion ofthe. GROSS, bar.. which connects the roar .ends ,of the -sdoloors of. therchassis together with the connecting meinloor` for Securingtho.. end of tho.- Grossi bar to the end ofthe sidebar.

Fig. 4e is a sectionon the line; 4-4A-Iot Fig. 3, and

Fig. 5 is.: a` perspective view of the ccnl- 60 nection( which is Vsecured to the, eIllSK-,oji the two cross bars= Referringto the accompanyingidrnvvings; The numeral 1, indicatesthe side ofan,` automobile chassis, which may be of anyogy 65 the forms in common use; and 2. indicates. the rear axle,l the` end portions of4 which restl upon, and are secured by'` U-bolt connections 3,'to semi-elliptic side springs@ midway Q the length of the saidsprings,

The forward ends of the springs 4L arev preferably secured directly to vbolts'5 which .are supported in brackets 6 which are, bolted to.. the( side bars, and the rear ends of thel springs are secured directly to bolts7 which 75 are supported in the outer ends of Connections 8, which are securedupon the ends ci af crossbar 9;, which isl preferably hollow, andI rectangular in crosssection,

'llhevconnections or castingsf` are identicalV so in construction, each comprising yoke shaped body portion 10,.which receiveVv the end portion oi the cross bar 9, and is rigidly secured thereto by bolts 11 which pass,`

through elongated holes 1 2 in the sides or 85 Y the said body portion Y 10, and through bolt holes in the end portions of theV crosshbarj, tho, elongated. holes 1 2., compensating.; for

a y slight varatons-atho. positions the.4 bolt holes 'inwthererossbar. i'

Tho 11p-nor and. lovor odsos ofthe. Sido. members 'of tho Said.' body' portoul, tonni: nate in narrow longitudinal: 'llrovortod flaneoo-1s3vhoh engage, tho v-mios. bar: and oo@ Corruption wththo bolts vil.l to lorieo5 vent a sagging movement of the:V com etioiisf 8 Wthro'sieot to the ond'sof theoross 9,- The outer. ond of oaoh connection 8; terminates man L-sliapod proiooton la, the, end member ofwhich is provided cer-itrally.` 100 with a` smooth bolt hole 15 which is in axial lino with o throadodboltholol the adje:

cent end of the yoke shaped body portion of the connections, and the bolts 7 which support the outer ends of the springs el, are passed through the smooth holes 15, and screwed into the threaded holes 16, as will be seen by reference to the drawings.

The rear ends of the side bars 1 are also connected by a cross bar 17, to the ends of which connections or castings 18 are secured, by bolts 19, and these connections 18 are identical in construction with the connections 8, and therefore, require no separate description. The L-shaped ends 14 of the connections 18 support bolts 20, which pass through the usual apertured rear ends of the side bars land thus form a pivotal connection between the cross bars 17 and the rear ends of the side bars. An elliptic spring 21 is interposed between the cross bars 9 and 17, and midway of the length of said bars, and is secured to the said bars by lJ-bolts 22 and 23 which secure, respectively, the lower member of the spring 21 to the cross bar9, and the upper member of the spring to the cross bar 17. It will thus be seen from the foregoing description, taken in connection with Figures 1 and 2 of the drawings, that the frame of the car is spring-supported at three points, namely, at the forward ends of the two side springs 1l, and upon the elliptic spring 21.

As the elliptic spring Q1 is located. midway between the two rear wheels, a shock resulting from obstructions encountered by both rear wheels, is received by the side Vsprings and transferred to the elliptic spring which further cushions the said shock, the diminished force of which is passed on to the side bars at a point midway between their ends where the load is equalized. As the front ends of the side springs are connected to the bolts 5 in the rigid brackets 6, the lengthening-of the springs under compression causes an outward swing of the cross bar 9 and elliptic spring 21 and turning movement of the cross bar 1T on the bolts 20, thus obviating the need of a shackle at either end of the side springs.

When either rear wheel encounters an obstruction independently of the other rear wheel, the shock is first received by the side spring and then transmitted to the elliptic spring which further cushions the shock and delivers its spent force at a point midway between the rear ends of the side bars, thus practically eliminating the side bump or `jolt which would have been imparted to that side of the car whose wheel encountered the obstruction, if the rear end of the side spring had been attached to the rear end of the side bar, as in spring constructions in present use. Moreover, the elliptic spring acts as an evener' when the rear wheels encounter obstructions, independently, that is,

the upward movement of one end of the elliptic spring, due to the upward thrust oit one of the side springs, causes a` downward thrust on the opposite side spring, so that the cushioning effect of all three springs is utilized.

The improved spring arrangement not only possesses all of the good points of the side and cross spring construction, but it gives greater resiliency of spring action under all road conditions, and also prac tically eliminates the side jolts which are inevitable where both ends of the side springs are connected to the side bar.

Having described my invention, what l claim as new, and desire to secure by Letters Patent, is:

1. In automobile spring' construction, the combination with the body supporting side bars and the axle, of semi-elliptic springs which are secured intermediate of their ends to said axle, and at their forward ends to the side bars, a cross bar pivotally at* tached at its ends to therrear ends of said springs, a cross bar pivotally attached at its ends to the rear end of the side bars, and an elliptic spring interposed between the cross bar-s midway between their ends and secured to said cross bars.

2. In automobile spring construction, thc combination with the body-supporting side bars and the axle of semi-elliptic springs which are secured intermediate of their ends to said axle and at their forward ends to the side barsv a cross bar and pivot bolts in the ends of said cross bar for support-- ing the rear ends of said springs; a cross bar and pivot bolts in the ends thereof which extend through the rear ends of the side bars, and an elliptic spring interposed between said cross bars midway between their ends, and secured to said cross bars.

In automobile spring construction, the combination with the body supporting side bars and the axle, and semi-elliptic springs secured at their forward ends to the sideI bars, and intermediate of their ends to the axle; of a cross bar having castings bolted to its ends, which are provided with pivotl bolts which pass through the rea-r ends oi" said springs; a cross bar having' castings in its ends provided with pivot bolts which pass through the rear end of the said side bars; and an elliptic spring which is interposed between said cross bars midway of their ends and secured to said cross bars,

if ln automobile spring construction, the combination with the body supporting side bars and the axle and semi-elliptic springs which are attached at their forward ends l to the side bars` and intermediate of their ends, to the axle, of means for connecting the rear ends of said springs consisting of a cross bar having yoke shaped castings extending over and bolted to its end portions `und provided With L-shaped projections and bolts supported in said L-shaped projections, and the closed end of said yoke, which pass through the rear ends of said springs; a cross bar having similar castings on its ends and bolts carried thereby which pass through the rear ends of said side bers, and an elliptic spring which is interposed between said Cross bars intermediate of ltheir ends and secured to sind cross bars.

In testimony whereof I affix my signa-k ture in presence of two Witnesses.

FRANK N. SPRAGUE. litnesses: v

G. SARGENT ELLIOTT, EMILY ROBERTS HANNING. 

